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USING FLASH CS4 PROFESSIONAL
Best practices
Note:
If you enter a description for the main SWF file, this description is read each time the SWF file refreshes. You can
avoid this redundancy by creating a separate informational page.
Inform the user about any navigational elements that change in the SWF file. Perhaps an extra button is added, or the
text on the face of a button changes, and this change is read aloud by the screen reader. Flash Player 7 and later supports
updating these properties by using ActionScript. You can update the accessibility information in your applications if
the content changes at runtime.
See also
“
Creating accessibility with ActionScript
” on page 312
Controlling descriptions and repetition
Designers and developers can assign descriptions for the animations, images, and graphics in a SWF file. Provide
names for graphics so the screen reader can interpret them. If a graphic or animation does not communicate vital
information to the SWF file (perhaps it is decorative or repetitive), or you outlined the element in the overall SWF file
description, do not provide a separate description for that element. Providing unnecessary descriptions can be
confusing to users who use screen readers.
Note:
If you divide text or use images for text in your SWF files, provide either a name or description for these elements.
If you have several nested movie clips that serve a single purpose or convey one idea, ensure that you do the following:
•
Group these elements in your SWF file.
•
Provide a description for the parent movie clip.
•
Make all the child movie clips inaccessible.
This is extremely important, or the screen reader tries to describe all the irrelevant nested movie clips, which will
confuse the user, and might cause the user to leave your website. Make this decision whenever you have more than
one object, such as many movie clips, in a SWF file. If the overall message is best conveyed using a single
description, provide a description on one of the objects, and make all the other objects inaccessible to the screen
reader.
Looping SWF files and applications cause screen readers to constantly refresh because the screen reader detects new
content on the page. Because the reader thinks the content is updated, it returns to the top of the web page and starts
rereading the content. Make inaccessible to screen readers any looping or refreshing objects that do not have to be
reread.
Note:
Do not type a description in the Description field of the Accessibility panel for instances (such as text) that the
screen reader reads aloud.
See also
“
Using Flash to enter accessibility information for screen readers
” on page 305
Updated 5 March 2009
